wp_mail doesnt work inside transition_comment_status

* UPDATE *
I have placed this function before the prev code

// define the wp_mail_failed callback 
function action_wp_mail_failed($wp_error) {
    return error_log(print_r($wp_error, true));
}

// add the action 
add_action('wp_mail_failed', 'action_wp_mail_failed', 10, 1);

Which helped me track the problem (using headers wrong).
I share this in the hopes this helpes anyone while debugging wp_mail()